Machine for sharpening files



P. JACKSON MACHINE FOR SHARPENING FILES Filed June 5, 1939. s Sheets-Sheet 2 m. m N (w QMME k.

Nov. 19, 1940.

Nov. 19, 1940. F; 2,222,034

MACHINE FO R SHARPENING FILES Filed June 5, 1939 5 Sheets-Sheet 3 ,FrarzlJacksbn Patented Nov. 19, 1940 UNITED STATES PATENT OFFICE 9 Claims.

This invention relates to machines for grinding files.

An object of the invention is the provision of a device for grinding the teeth of files in order to restore them to their former efiiciency, the machine including a cutter which may be positioned at various angles so that when the file holder is oscillated beneath the cutter, the teeth of the file will follow the revolving edge of the cutter in accordance with the shape of the teeth, means being employed for moving the file longitudinally of the holder in accordance with the spacing of the teeth of the file.

Another object of the invention is the provision of a machine for sharpening the teeth of files, commonly known as body and babbit, the file being mounted upon an oscillating holder which is moved across the path of a revolving cutter capable of being positioned at various angles to conform to the shape of the teeth of the file with a means operated by the oscillating holder for advancing the file and its holder so that a tooth may be operated upon one or more times depending upon the condition of the file,

a resilient means being employed for maintaining the file in proper position every time that the file is advanced one tooth for the sharpening operation.

A further object of the invention is the provision of a machine for sharpening files of various types whether straight or bowed and including an oscillating arm having a holder for the file which is moved back and forth beneath a revolving cutter operated independently of the means for oscillating the arm, a plurality of adjustments being employed for properly positioning the cutter in accordance with the type of teeth on the file, pawls for advancing the file on the oscillating arm tooth by tooth being actuated by the movement of the oscillating arm when said arm reaches its extreme limit of movement at either side of the revolving cutter, stops being associated with the table supporting the cutter for setting in motion a means for, causing actua- Thisinvention will be best understood from a consideration of the following detailed description, in View of the accompanying drawings forming a part of the specification; nevertheless, it is to be understood that the invention is not confined to the disclosure, being susceptible of-such changes and modifications as define no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings:

Figure 1 is a plan view of a cutting machine constructed in accordance with the principles of my invention,

Figure 2 is a longitudinal vertical section taken along the line 22 of Fig. 1,

Figure 3 is an enlarged plan view of the operating means for advancing the file for the cutting operations and shown in an inoperative position,

Figure 4 is a fragmentary vertical side view of the device shown in Fig. 1,

Figure 5 is a transverse vertical section taken along the line 5-5 of Fig. 1,

Figure 6 is a transverse vertical section of the holder showing the modified form of retaining the file on the holder,

Figure 7 is a transverse vertical section taken along the line 1-1 of Fig. 1,

Figure 8 is a longitudinal fragmentary vertical section taken along the line 88 of Fig. 7,

Figure 9 is a transverse vertical section taken along the line 9-9 of Fig. 1,

Figure 10 is a horizontal section taken along the line ll0 of Fig. 9,

Figure 11 is a View in perspective of the file holder removed from an oscillating arm,

Figure 12 is a fragmentary view in section showingv the position of the cutter in engagement with the tooth of a file.

Figure 13 is a fragmentary vertical section showing a bowed oscillating arm for supporting a similarly-shaped file, and,

Figure 14 is a fragmentary bottom plan view of the pivotal support for the oscillating arm.

Referring more particularly to the drawings, in designates a bed plate upon which are mounted a pair. of parallel tracks H and I2 which are formed of hardened steel and which have low friction bearing tracks as shown by the edges l3 formed of hardened steel. These tracks are secured in any approved manner to the table ID. The table is supported in any approved manner above the fioor of a building.

An oscillating arm l has plates I6 (Fig. 2) whichare formed of Wear-resisting material and since these plates are set in the pockets at the 'with threaded openings 3| to receive threaded the. holder without departing from-the spirit of underface of the arm 15 they may be removed when necessary. These plates are so positioned that they will ride over the upper edge of the tracks H and I2.

The arm l5 (Figs. 2 and 7) is oscillatably supported at an intermediate point by means of an adjustable plate I1 which has a hub 23 rotatably mounted on an axle l8 and this axle is provided with a collar 19 resting upon the bed plate II]. A threaded portion 20 of the axle is screwed into an opening in the bed plate and passes through an elongated slot 2! in the arm l5. The collar I9 is drawn up tight on the bed plate by a nut 22 for securing said axle in position.

The plate I1 is slidably mounted in a channel 24 formed in the arm 15 (Figs. 2 and '1). Cleats 25 received by notched portions at the sides of the plate l1 retain said plate on the bottom face of said arm. A lever Zla has an elongated slot 23a receiving a screw 24a secured to the arm 15. The lever is pivoted at 25a on the plate 11 so that when the free end of the lever 21a is rocked the arm [5 will be moved laterally at either side of the axle l8 for coordinating the exact center of the arc of the circle of the file tooth with the center of oscillation of the arm 15. After the adjustment has been made the screw 24a is tightened to hold the arm centered. Any suitable type of bearings may be employed between the axle 18, the hub l1 and the collar [9, if desired.

A file holder 26 (Fig. 11) consists of an elongated bar having a centrally and longitudinally disposed channel 21 to receive a file F. Flanges 28 project laterally from the bar 26 and in substantially the same plane with the channel 21 to form angularly-shaped grooves 29 which are received by longitudinally disposed tracks 30 mounted upon the oscillating arm [5 so that when the holder 23 is moved along said arm it will be guided in a definite direction. This holder is provided bolts which pass through openings in the file to secure the file rigidly to the holder. While the grooves 29 and the tracks 39 are shown as having ,right angular faces, these faces may be inclined at an acute angle to form a dove-tailed connection between a holder and the oscillating arm 15.

Referring more particularly to Fig. 6, it will be seen that a modified form of the securing means ,for the files is provided and, a holder 25a has 'cleats 3| removably secured to the flanges 28a and the pointed ends 32 of these cleats are adapted to be received by notches 33 formed in the longitudinal walls of a file F. Various types of means may be employed for securing the file to the invention.

In order to maintain the file when it is being operated in a predetermined position during the cutting operation, a resilient means is employed and this means consists of a housing 35 secured to one end of the oscillating arm 15 (Figs. 9 and A coil spring 36 is located in the housing and is wound up with one end being connected to a shaft 31 while the other end is connected to the housing. A grooved pulley 38 is secured to the shaft 31 within the housing 35 upon which is wound a cable 39 which extends through an opening 40 in the housing and is provided with a hook 41 adapted to be received by an eye 42 secured to the adjacent end of the holder 26 so that the spring will always tend to pull the holder towards the housing 35 during the cutting operation.

The arm I5 is oscillated by means of a link 45 (Fig. 1) which is pivotally connected to a lug 46 projecting from one side of said arm. This shaft is operated through a transmission mechanism or speed reducer 5B and a motor 5| and all of these parts are carried by the standards in the usual manner which support the work table Ill. The motor may be of any type but preferably an electrical motor is employed for the purpose. The link 45 has a pivotal connection at 41 with an arm or lever 48 secured to a shaft 49. This shaft is revolved by a speed reducer 50 operated by the motor 5|. The motor, speed reducer and shaft are located beneath the work table 10 and are carried by the usual framework which supports said table. A circle in dotted lines represents the path through which the pin or pivotal connection 41 moves during the rotation of the shaft 29. The dotted line positions of the arm I5 and the link 45 indicates the extreme positions of these members during a complete rotation of the lever 48.

Thefile is advanced periodically either once during the rotation of the lever 48 or twice, depending upon the condition of the file. If the file is in poor condition, the teeth of the file are sharpened twice during each rotation of the lever 48. Otherwise the file is advanced every 180 of rotation of the arm, so that each tooth is sharpened during half of the complete oscillating movement of the arm 15. I

The file is advanced by means of pawls ,55 and 56 (Figs. 1 to 4, inclusive), which engage the teeth of the file so that when these pawls advance one step, the file will be advanced likewise one step as Well as the holder 26 against the tension of the spring 39 towards the right in Fig. 2.

The pawls 55, and 56 are mounted in horizontally disposed arms 51 and 58 which extend horizontally and have their free ends carrying the pawls located over the file holder 26 so that the pawls may engage the teeth of the .file for periodically shifting the file longitudinally of the arm l5. These arms are secured to the upper ends of the respective rock shafts 59 and 60 which are mounted in bearings in a bar BI extending longitudinally of the arm and secured to one side edge of said arm by a threaded bolt 62. A ball crank lever 63 is. rigidly secured to the shaft 59 below the bottom of the arm and above the upper surface of the work table 10. The free end of the arm 64 of the bell crank lever 63 has its' free end located adjacent a T-shape-d lever 65 which is pivotally mounted at 66 on one end of the bar 61. A link 61 has one end pivotaly connected, respectively,with the bell crank 63, as shown at 68. The other end of the link 61 is pivotally connected at 69 with a lever 10 rigidly connected to a shaft 60 and located below the oscillating arm I5, as shown in Figs. 2 and 4. Thus it will be seen when the arm 64 of the bell crank 63 is rocked the link 61 will impart a similar rocking motion to the lever 16 so that both pawls 55 and 56 when engaged with the teeth 1| of the file F will shift the file a distance equal to the space between a pair of the teeth.

A pair of retaining pawls 12 and 13 are carried by horizontally disposed arms 14 and 15, respectively, which extend over the face of the file F and are adapted to engage the teeth of the file for retaining the file against movement longitudinally. The arm 14 is rigidly connected with a weighted lever 16 and this lever is pivotally mounted at 11 on a block 18 secured to the side wall of the oscillating arm 15 and opposite the bar 61.

The arm 15 is rigidly connected with a Weighted lever I9 which is pivotally mounted on a block 89 secured to the side wall of the arm I5.

A pair of stops BI and 82 are secured to the work table I!) in spaced relation on radii passing through the center of the axle I8 with the radius extending from the said center to the center of the block 32 being less in length than the radius extending between the center of said axle to the center of the block SI. The block 8| is provided with an elongated slot 83 to receive a bolt 84 which is threaded into the top I so that said block may be adjusted toward or away from the position shown in Fig. 1 whereby it may be moved to a position so that the T-shaped lever 55 will not be engaged by said block. This is also true of the block 82 which has an elongated slot 85 to receive a bolt 86 threaded into a passage in the top I9. The block 82 is in a position to directly engage the arm 64 of the bell crank lever 63while the block SI engages one end of the T-shaped lever 65 so that when this lever is rocked the opposite end will engage the arm 64 of the bell crank 63 and rock said bell crank for a purpose which has been explained.

A block 99 for adjustably supporting a bracket M which carries a cutter 92 has a dove-tailed slot 93 receiving a complementarily formed guide 94 so that the block 90 may be shifted longitudinally of the member 94 for adjusting the position of the cutter 92 longitudinally of the file F carried by the arm I5, as shown more particularly in Figs. 1, 7 and 8.

A bolt 95 is threaded into a passage 96 in the block 99 and has a reduced portion 91 received :within a bearing bracket 98. An operating head 99 is secured to the outer end of the bolt for rotating said bolt to cause the block 90 to move longitudinally of the top I0 for properly adjusting the cutter 92 with respect to the teeth running transversely of the file F.

In order to center the cutter with respect to the teeth of the file the guide 94 is adapted to be adjusted along a line which is at right angles to the adjustment of the block 90. A- pair of rails II!!! are secured at IOI to the top I0 and these rails are received by grooves I92 formed in the bottom face of the member 94 which is held in place on the table by means of bolts III-3' passing through elongated slots I04 formed in the opposite ends of the member 94, as shown in Fig. 8. A washer I05 is located between the upper surface of the member 94 and a head I06 formed at the outer end of each ofthe bolts I03. After the member 94 has been properly positioned, the bolts are tightened for rigidly holding said member against movement.

The cutter 92 is mounted on a shaft Ill! which extends through a bearing block III and is provided with a pulley H2 at the oposite end. A belt H3 is trained on the pulley H2 and also a pulley H4 driven by a shaft H5 is connected with a motor II6. This motor is carried in any approved manner upon the framework which normally supports the work table II]. The motor is provided with the usual slotted base ill with bolts H8 securing the case in position but permitting longitudinal adjustment of the base for properly positioning the motor when necessary.

The bearing block III, the shaft III! and the cutter 92 have a sliding connection with an auxiliary bracket I29 which is pivotally mounted on a bolt I2I carried by the bracket 9|. The bearing block, as shown more particularly in Fig. 1, has a dove-tailed connection as shown at I22 with the bracket I so that the block III may be adjusted vertically when desired. A threaded bolt I23 is threaded into an opening I24 onan arm I25 projecting from the block III and the upper end, of this belt has a pair of collars I26 and I2! embracing opposite sides of an extension I28 of the bracket I20 so that this bolt may be revolved and as the bolt is threaded into the arm I25 the block III may be adjusted vertically by rotating a head on the outer free end of the bolt I23.

ghe lower end of the bracket M is secured by means of a bolt I 29 to the adjustable block 99.

The cutting disc 92 may be adjusted relative to the'vertical means of the nut I30 and the Washers I3I in order to properly position the cutter so that it will eificiently sharpen the teeth of the file.

The operation of my device is as follows: The file F is placed in the holder 26 and secured either by means of bolts passing through openings in the file and threaded into openings 30 and 3| in said holder which are formed in the base of the channel 21. After the file has been placed in the channel various adjustments are made so that the sharpening wheel 92 will be properly positioned with respect to the teeth of the file and any of these adjustments may be made by moving the block in two directions at right angles to each other and further adjustments may be made by properly positioning the bearing block I II through the medium of the bolt I2I and the nut I2Ia..' The vertical position of the cutter is adjusted by manipulating the bolt I23.

The angular position of the cutter as shown in Fig. 2 is made by rocking the bracket I29 to the proper angle after the nut I2Ia has been loosened. After this the nut is tightened and the wheel 92 will maintain its proper angular relation with the teeth of the cutter.

The file after it has been placed within the holder 26 is moved along the arm I5 against the tension of the spring 36 in the housing until the first tooth adjacent the handle I35 is positioned in operative relation with the wheel 92. At this time the outer pawl I3 will engage a tooth a short distance away from the cutter Wheel 92 and maintains the'file against rearward motion by the tension of the spring 36. At this time the advancing or actuating pawl 56 is in engagement with a tooth adjacent the pawl I3 which is in engagement with a tooth of the file so that the parts are in operative position to start'the motors SI and H6.

When the motors begin to operate, the arm 48 will move the link to cause oscillation of the arm I5 and this arm moves between the dotted line positions shown in Fig. l and across the path of the revolving cutter. The stops ill and 82 are in a position to be engaged respectively by the T-shaped lever 65 and the arm 64 of the bell crank 63 when the arm reaches its limit of movement of oscillation. A tooth is acted upon by the cutter when the arm I5 moves from the dotted line position indicated at A to,

the dotted line position indicated at 3 in Fig. 1. When the opposite end of the arm reaches the dotted line position as indicated by B, the arm 64 of the bell crank 63 will be engaged by the stop 82 and the bell crank lever will be rocked as will be the levers Iii through the connecting link 61. When these levers are rocked the arms 51 are moved in the direction indicated by the arrow in Fig. 3-so that the p-awls 56 will move the fileF the distance amounting to the space between a pair of teeth so that whenthe pawl I3 'falls behind the next tooth the pawl 56 will also drop into the tooth directly behind the tooth which has been treated until the oscillating arm I5 is moved over to the stop 8| whence the T- shaped lever 65 will be rocked and this in turn rocks the bell crank lever again for advancing the file one step against the tension of the spring 36.

As soon as the teeth adjacent the handle I34 of the file reach the pawl 55 both pawls '55 and 56 will operate to advance the file. At each completion of the movement of the file step by step the pawl 13 will engage a tooth and hold the file against slippage. When the file is sufiiciently advanced both pawls I2 and 13 will engage the teeth of the file for retaining the file against slippage.

The operation just described where a pair of teeth are sharpened by the to and fro movement of the oscillating arm I5, the file is in such condition that only one cutting operation is re-- quired for each tooth. On the other hand where the file is in such condition that it is necessary to move the teeth of the file back and forth under the cutter before the teeth are properly sharpened, one of the stops 8! or 82 is moved out of position so that it will not be engaged by the relative operating elements on the arm l5 whereby the arm will be rocked back and forth and the cutter will acton the tooth at each oscillation of the arm.

After the various adjustments have been made for the cutter 92 it may be necessary to tighten or loosen the belt I I3 and this is done by adjusting the position of the motor I I6.

Referring more particularly to Fig. 13, it will be seen that the holder 26b is curved to conform to the curvature of the file F2 known as a body type.

The carriage or arm 15 moves the file F to th limits of movement of the arms upon opposite sides of a line passing through the center of the table top ill beyond the confines of the grinding wheel 92 so that the file may be advanced when the teeth of the file are out oi contact with the grinding wheel. .1

I claim:

l. A file sharpening machine comprising an oscillatable carriage, means slidably supporting a file on said carriage, a grinding wheel rotatably mounted to engage the teeth of the file, means rotating the wheel, means periodically oscillating the carriage beneath the wheel, means engaging the teeth of the file for advancing the file supporting means and the file along the carriage stepby-step, means operated when the carriage is oscillated for actuating the advancing means, said wheel being inclined to the vertical, and means adjustably positioning theangle of inclination of the wheel relative to'the teeth.

2. A file sharpening machine comprising an oscillatable carriage, means slidably supporting a file on said carriage, a grinding wheel rotatably mounted to engage the teeth of the file, means rotating the wheel, means. periodically oscillating the carriage beneath the wheel, means engaging the teeth of the file for advancingthe file supporting means and the file along the carriage step-by-step, means operated when the carriage is oscillated for actuating the advancing means,

a table upon which the carriage is oscillatablymounted, a block mounted on the table at the center of oscillation of the carriage, a shaft carried by the block, said wheel being mounted on the shaft.

3. A file sharpening machine comprising a table, 'an oscillatable carriage, means pivotally mounting the carriage on the table, a holder slidably supporting a file on the carriage, a bell crank pivotally mounted on the carriage and providedwith a pawl for advancing the holder and file along the carriage step-by-step, means retaining the file in position at each advanced step, a lever. pivoted on the carriage and provided with a pawl engaging a tooth on the file, a link connecting said lever with the bell crank, means causing rocking of the bell crank at the limit of oscillation of the carriage, means oscillating the carriage through a predetermined angle, a grinding wheel contacting the teeth of the file as it rocked to and fro, and means rotating the wheel.

4. A file sharpening machine comprising a table, an oscillatable carriage, means pivotally mounting the carriage on the table, a holder slidably supporting a file on the carriage, a bell crank pivotally mounted on the carriage and provided with a pawl for advancing the holder and file along the carriage step-by-step, means retaining the file in position at each advanced step, means causing rocking of the bell crank at the limit of oscillation of the carriage, means oscillating the carriage through a predetermined 0 angle, a grinding wheel contacting the teeth of the file as it is rocked to and fro, and means rotating the wheel.

5.A file sharpening machine comprising a table, an oscillatable carriage, means pivotally mounting the carriage on the table, a holder slidably supporting a file on the carriage, a bell crank pivotally mounted on the carriage and provided with a pawl for advancing the holder and file along the carriage step-by-step, means retaining the file in position at each advanced step, means causing rocking of the bell crank at the limit of oscillation of the carriage, means oscillating the carriage through a predetermined angle, a grinding wheel contacting the teeth of the file as it is rocked to and fro, means rotating the wheel, and spaced tracks mounted on the table and supporting the oscillating arm above the table.

6. A file sharpening machine comprising a table, an oscillatable carriage, means pivotally mounting the carriage on the table, a holder slidablysupporting a file on the carriage, a bell crank pivotally mounted on the carriage and provided with a pawl for advancing the holder and file along the carriage step-by-step, means retaining the file in position at each advanced step, means causing rocking of the bell crank at the limit of oscillation of the carriage, means oscillating the carriage through a predetermined angle, a grinding wheel contacting the teeth of the file asit is rocked to and fro, means rotating the wheel, resilient means on the carriage connected to the holder for urging said holder in anopposite direction from the advancement by the pawl.

' 7. A file sharpening machine comprising a table, an oscillatable carriage, means pivotally mounting the carriage on the table, a holder slidably supporting a file on the carriage, a bell crank pivotally mounted on the carriage and provided with a pawl for advancing the holder and file along the carriage step-by-step, means retaining thefile in position at each advanced step, a lever pivoted on the carriage and provided with a pawl engaging a tooth on the file,

a link connecting said lever with the bell crank, spaced stops mounted on the table and located at the limits of movement of the oscillating carriage, means on the arm and engageable with one of the stops for causing actuation of the bellcrank, the other stop adapted to be engaged directly by the bell crank for causing actuation of the bell crank, means oscillating the carriage through a predetermined angle, a grinding wheel contacting the teeth of the file as it is rocked to and fro, and means rotating the wheel.

8. A file sharpening machine comprising a table, an oscillatable carriage, means pivotally mounting the carriage on the table, a holder slidably supporting a file on the carriage, a bell crank pivotally mounted on the carriage and provided with a pawl for advancing the holder and file along the carriage step-by-step, means retaining the file in position at each advanced step, a lever pivoted on the carriage and provided with a pawl engaging a tooth on the file, a link connecting said lever with the bell crank, spaced stops mounted at the limits of movement of the oscillating carriage, means on the arm and engageable with one of the stops for causing actuation of the bell crank, the other stop adapted to be engaged directly by the bell crank for causing actuation of the bell crank, means oscillating the carriage through a predetermined angle, a grinding wheel contacting the teeth of the file as it is rocked to and fro, and means rotating the wheel, said stops being adjustably mounted so that one of the stops may be moved out of the path of the carriage whereby each.

tooth of the file will be advanced by the back and forth movement of the carriage,

9. A file sharpening machine comprising a table, an oscillatable carriage, means pivotally mounting the carriage on the. table, a holder slidably supporting a file on the carriage, a bell a predetermined angle, a grinding wheel contacting the teeth of the file as it is rocked to and fro, and means rotating the wheel.

FRANK P. JACKSON. 

